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Sm-Nd and zircon SHRIMP U-Pb dating of Huilanshan mafic granulite in the Dabie Mountains and its zircon trace element geochemistry

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science China earth sciences 2005年第12期48卷 2081-2091页

作者： HOU Zhenhui1, LI Shuguang1, CHEN Nengsong2, LI Qiuli1 & LIU Xiaoming3.1. school of earth and space sciences, university of science and {3. of China, hefei 23.026, China 2. The Key laboratory of Continental Dynamics of the Ministry of Education, Northwest university, Xi’an 710069, China 3. Faculty of earth sciences, China university of Geosciences, Wuhan 43.074, China school of earth and space {3. University of Science and Technology of China Hefei China The Key laboratory of Continental Dynamics of the Ministry of Education Northwest University Xi’an China Faculty of earth sciences China University of Geosciences Wuhan China

The mafic granulites from Huilanshan are outcropped on the center of the Luotian dome in the northern Dabie Mountains. The Sm-Nd isochron defined by granulite-facies meta-morphic minerals (garnet + clinopyroxene + hypersthene) yields an age of 13. ± 18 Ma indicating the early Cretaceous granulite-facies metamorphism. The cathodoluminescence (CL) images of zircons from the granulite show clearly core-mantle-rim structures. The zircon cores are charac-terized by typical oscillatory zoning and highly HREE enriched patterns, which suggests their magma origin. Some zircon cores among them with little Pb loss give SHRIMP U-Pb ages rang-ing from 753.to 780 Ma, which suggests that the protolith of Huilanshan granulite is Neopro-terozoic mafic rocks. The zircon mantles usually cut across the oscillatory zone of the zircon cores have 3.10 times lower REE, Th, U, Y, Nb and Ta contents than the igneous zircon cores but have high common Pb contents. These characteristics suggest that they were formed by hydrothermal alteration of the igneous zircons. The part of zircon mantles with little Pb loss give a similar SHRIMP U-Pb age (716―780 Ma) to the igneous zircon cores, which implies that the hydrothermal events occurred closely to the magmatic emplacement. In view of the strong early Cretaceous magmatism in the Luotian dome, consequently, the Huilanshan mafic granulite was formed by heating of the Neoproterozoic mafic rocks in mid-low crust, which caused the granu-lite-facies metamorphism underneath the Dabie Mountains. The similarity between the granulite metamorphic age (13. ± 18 Ma) defined by Sm-Nd isochron and K-Ar age of 123.127 Ma given by amphible from the gneiss in Luotian dome suggests a rapid uplifting of the Luotian dome, which may result in further exhumation of the ultrahigh pressure metamorphic rocks in the Dabie Mountains.

关键词： Dabie orogen, granulite, zircon U-Pb ages, Sm-Nd age.

Re-Os isotopic system and formation age of subcontinental lithosphere mantle

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Chinese science Bulletin 2000年第3期45卷 193-200页

作者： ZHI XiachenDepartment of earth and space sciences, {3. of science and technology of China, hefei 23.026, China Advance Research Center for earth science and Astronomy, USTC, Third World Academy of science, hefei 23.026, China laboratory of Chemical Geodynamics, USTC, hefei 23.026, China Department of earth and space sciences University of Science and Technology of China Hefei China Advance Research Center for earth science and Astronomy USTC Third World Academy of Science Hefei China laboratory of Chemical Geodynamics USTC Hefei China

The determination of the formation age of subcontinental Lithosphere Mantle (SCLM) is a widely concerned issue in mantle geochemistry. it is difficult to obtain the formation age of SCLM using lithophile isotopic systems such as Rb-Sr, Sm-Nd, U-Th-Pb, ete., but as siderophile elements, the Re-Os isotopic system provides a powerful tool for that work. Here a comprehensive review on the recent development in Re-Os dating for SCLM has been given.

关键词： Re-Os isotopic dating subcontinental lithospheric mantle mantle derived peridotites Re depleted model age whole rock isochronological age.

Latest progress on interactions between VLF/ELF waves and energetic electrons in the inner magnetosphere

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science China earth sciences 2010年第3期53卷 317-326页

作者： XIAO FuLiang1,2, ZONG QiuGang3. SU ZhenPeng4, TIAN Tian3.& ZHENG HuiNan4 1 school of Physics and Electronic sciences, Changsha university of {3. and technology, Changsha 410004, China 2 State Key laboratory of space Weather, Chinese Academy of sciences, Beijing 100190, China 3.Institute of space Physics and Applied technology, Peking university, Beijing 100871, China 4 CAS Key Lab for Basic Plasma {3., school of earth and space sciences, university of {3. and technology of China, hefei 23.026, China school of Physics and Electronic sciences Changsha University of Science and Technology Changsha China State Key laboratory of space Weather Chinese Academy of Sciences Beijing China Institute of space Physics and Applied technology Peking University Beijing China CAS Key Lab for Basic Plasma science School of Earth and Space Sciences University of Science and Technology of China Hefei China

Interactions between very/extremely low frequency (VLF/ELF) waves and energetic electrons play a fundamental role in dynamics occurring in the inner magnetosphere. Here, we briefly discuss global properties of VLF/ELF waves, along with the variability of the electron radiation belts associated with wave-particle interactions and radial diffusion. We provide cases of electron loss and acceleration as a result of wave-particle interactions primarily due to such waves, and particularly some preliminary results of 3. evolution of phase space density from our currently developing 3. code. We comment on the existing mechanisms responsible for acceleration and loss, and identify several critical issues that need to be addressed. We review latest progress and suggest open questions for future investigation.

关键词： wave-particle interaction VLF/ELF waves energetic electrons acceleration and loss inner magnetosphere

Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone

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science China earth sciences 2004年第3期47卷 265-271页

作者： GE Heping1, SUN Yan1, LU Xiancai1, ZHU Wenbin1, GUO Jichun1, LIU Deliang2 & Chi-yuen Wang3.1. Department of earth sciences, Nanjing university, State Key {3. of Mineral Deposit, Nanjing 210093. China 2. Department of earth and space sciences, university of science and technology of China, hefei 23.026, China 3. Department of Geology and Geophysics, university of California, Berkeley, CA 94720, USA Department of earth sciences Nanjing University State Key Lab. of Mineral Deposit Nanjing 210093 China Dept. of earth and space sciences Univ. of Science/Technology of China Hefei 230026 China Department of Geology and Geophysics University of California Berkeley CA 94720 United States

Based on the observation of the deep bore cores sampled from the State of Cali-fornia, USA, preferred arranged particulate concentration belts were found in the ultra-slipping lamellae. And the same phenomenon was found again later in the bore cores from the petroleum basin in the Northern Shaanxi Province. It may be the product of the dynamic processes involv-ing tumbling, grinding and compresso-shearing functions, so the spherical particulates with ul-tra-size of nm and mm are called grinding grain. The formation of the grinding grains is related with the ductile-brittle deformation, the lateral pressure of the slipping, and the very low grade of dynamic metamorphism of the rocks. Based on the systematic analysis, it is indicated that some elements like Nb and Ta are enriched in the grinding grains in the granitic rocks because of the chemical differentiation, and that the slipping lamellae bearing grinding grains in mudstone with smear efficiency prove a perfect seal for oil and gas reservoirs. Meanwhile, the paper provides bases for the studies on the fast stick-slip movement and shear paradigm.

关键词： slipping lamellae, grinding grain texture, ductile-brittle deformation, smear efficiency.

Prediction method for October 2003.solar storm

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science China(Technological sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2, 3. WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2 1. State Key laboratory of space Weather, Center for space {3. and Applied Research, Chinese Academy of sciences, Beijing 100080, China 2. Graduate school, Chinese Academy of sciences, Beijing 10003., China 3. Institute of Meteorology, PLA university of {3. and technology, Nanjing 211101, China State Key laboratory of space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Graduate school Chinese Academy of Sciences Beijing China Institute of Meteorology PLA University of Science and Technology Nanjing China

Aiming at two intense shock events on October 28 and 29, 2003. this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

The δ^(18)O variation of a stalagmite from Qixing Cave,Guizhou Province and indi-cated climate change during the Holocene

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Chinese science Bulletin 2001年第22期46卷 1904-1908页

作者： CAI Yanjun, ZHANG Meiliang, PENG Zicheng, LIN Yushi, AN Zhisheng, ZHANG Zhaofeng & CAO YunningState Key laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710054, China Karst Dynamics laboratory, Ministry of Land and Resources, Guilin 541003. China Department of earth and space science, university of science & technology of China, hefei 23.023. China State Key laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Karst Dynamics laboratory Ministry of Land and Resources Guilin China Department of earth and space science University of Science & Technology of China Hefei China

A stalagmite from Qixing Cave, Guizhou Province was dated with the TIMS U-series method and its oxygen isotope composition was analyzed. On the basis of the ages and the variations of the δ18O of the stalagmite, the climate change of the last 7.7 ka has been reconstructed in this area: 7.7-5.8 ka, summer monsoon maximum period; 5.8-3.8 ka summer monsoon weakening period; 3.8-0.15 ka, weakened summer monsoon and high amplitude climate fluctuations period. We put forward that the increasing trend of δ18O of the stalagmite reflected not only the weakening of the summer monsoon, which was caused by the decreasing of solar radiation in the Northern Hemisphere, but also the possibly decreasing contribution of the southwest monsoon to the rainfall of this area. These results are consistent with the output of the numerical climate-model modeling. The high amplitude fluctuation of the δ18O may imply the quick shift of the contributions of different moisture sources to the precipitation in this area.

关键词： stalagmite Holocene southwest monsoon.

Statistical study on the relationship between halo CME and coronal dimming

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science China(Technological sciences) 2010年第7期53卷 2020-2024页

作者： LIU Kai1, XIA LiDong2, CHEN Yao2 & SONG HongQiang2 1 school of earth and space sciences, university of science and {3. of China, hefei 23.026, China 2 Shandong Provincial Key laboratory of Optical Astronomy and Solar-Terrestrial Environment, school of space science and Physics, Shandong university at Weihai, Weihai 264209, China school of earth and space {3. University of Science and Technology of China Hefei China Shandong Provincial Key laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Shandong University at Weihai Weihai China

The data from SOHO/EIT and SOHO/LASCO observations are used to determine the relationship between coronal dimming and full halo CME (coronal mass ejection). The events of full halo CME examined in this study were observed by LASCO co-ronagraphs and taken from the CD AW CME catalog from 1996 to 2008. Dimming events are identified by using difference images taken by EIT at the 195 A passband. We found strong relationship between full halo CMEs and the coronal dimming events, with up to 93.3. of the front-side halo CMEs associated with the EIT 195 A dimming events. Full halo CMEs that show no clear signatures of dimming usually have lower sky plane velocities (<700 km/s) compared to the mean velocity of CMEs associated with dimming.

关键词： Sun coronal mass ejection coronal dimming extreme-ultraviolet

Numerical study of the auroral particle transport in the polar upper atmosphere

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science China(Technological sciences) 2008年第10期51卷 1759-1771页

作者： CAI HongTao1,2, MA ShuYing1,2 & PU ZuYin3.1 school of Electronic Information, Wuhan university, Wuhan 43.079, China 2 Key laboratory of Geo{3. Environment and Geodesy, Ministry of Education of PRC, Wuhan 43.079, China 3.4}, Peking university, Beijing 100871, China school of Electronic Information Wuhan University Wuhan China Key laboratory of Geospace Environment and Geodesy Ministry of Education of PRC Wuhan China school of earth and space {3. Peking University Beijing China

Starting from the Boltzmann equation and with some reasonable assumptions, a one-dimensional transport equation of charged energetic particles is derived by taking account of major interactions with neutral species in the upper atmosphere, including the processes of elastic scattering, the excitation, the ionization and the secondary electron production. The transport equation is numerically solved, for a simplified atmosphere consisting only of nitrogen molecules (N2), to obtain the variations of incident electron fluxes as a function of altitude, energy and pitch angle. The model results can describe fairly the transport characteristics of pre-cipitating auroral electron spectra in the polar upper atmosphere; meanwhile the N2 ionization rates calculated from the modeled differential flux spectra also exhibit good agreements with existing empirical models in terms of several key parameters. Taking the energy flux spectra of precipitating electrons observed by FAST satellite flying over EISCAT site on May 15, 1997 as model inputs, the model-calculated ionization rate profile of neutral atmosphere consists reasonably with that recon-structed from electron density measurements by the radar.

关键词： aurora particle precipitation polar upper atmosphere electron transport equation numerical simulation

Sm-Nd isotopic ages of Tiqiushan eclogites in Xinyi region and its geological significance

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Chinese science Bulletin 1999年第S2期44卷 144-146页

作者： WANG Yinxi~(1,2), YANG Jiedong~(1,2), TAO Xiancong~(1,2), GE Ningjie~4, CHEN Peirong~3. FAN Chunfang~3.and LI Jianhua~5 1. Center of Modern Analysis, Nanjing university, Nanjing 210093. China 2. State Key laboratory for Research of Mineral Deposits, Nanjing university, Nanjing 210093. China 3. Department of {3. science, Nanjing university, Nanjing 210093. China 4. Department of {3. and space sciences, university of science and technology of Chian, hefei 23.026, China 5. No.5 Geological Party of Jiangsu Province, Xuzhou 221005, China Center of Modern Analysis Nanjing University Nanjing 210093 China State Key laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China Department of earth and space sciences University of Science and Technology of Chian Hefei 230026 China Department of earth science Nanjing University Nanjing 210093 China No. 5 Geological Party of Jiangsu Province Xuzhou 221005 China

GEOLOGICAL scientists have paid much attention to the suture zones formed by collision between the Sino-Korean and Yangtze blocks because of the discovery of the ultrahigh pressue metamorphic (UHPM) rocksfrom northern Jiangsu Province (Su), southern Shandong Province (Lu) and the Dabie *** the age of 200-240 Ma is probably the best estimation for UHPM metamorphism in the DabieMountains, the primary intrusive and metamorphic ages of the complex from northern Jiangsu Provincehave not been determined before. Using the Sm-Nd isotopic dating method, our study is aimed at datingthe UHPM metanorphic event of northern Jiangsu Province and researching a probable relation between theUHPM rocks from the Dabie Mountains and the UHPM rocks from northern Jiangsu Province.

关键词： northern Jiangsu eclogite rocks Sm-Nd isotopic ages.